anotherim/src/de/gultsch/chat/persistance/DatabaseBackend.java

package de.gultsch.chat.persistance;

import java.util.ArrayList;
import java.util.List;

import de.gultsch.chat.entities.Conversation;
import de.gultsch.chat.entities.Message;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class DatabaseBackend extends SQLiteOpenHelper {

	private static DatabaseBackend instance = null;

	private static final String DATABASE_NAME = "history";
	private static final int DATABASE_VERSION = 1;

	public DatabaseBackend(Context context) {
		super(context, DATABASE_NAME, null, DATABASE_VERSION);
	}

	@Override
	public void onCreate(SQLiteDatabase db) {
		db.execSQL("create table " + Conversation.TABLENAME + " ("
				+ Conversation.UUID + " TEXT, " + Conversation.NAME + " TEXT, "
				+ Conversation.PHOTO_URI + " TEXT, " + Conversation.ACCOUNT
				+ " TEXT, " + Conversation.CONTACT + " TEXT, "
				+ Conversation.CREATED + " NUMBER, " + Conversation.STATUS
				+ " NUMBER)");
		db.execSQL("create table "+Message.TABLENAME+ "()");
	}

	@Override
	public void onUpgrade(SQLiteDatabase db, int arg1, int arg2) {
		// TODO Auto-generated method stub

	}

	public static synchronized DatabaseBackend getInstance(Context context) {
		if (instance == null) {
			instance = new DatabaseBackend(context);
		}
		return instance;
	}

	public void addConversation(Conversation conversation) {
		SQLiteDatabase db = this.getWritableDatabase();
		db.insert("conversations", null, conversation.getContentValues());
	}

	public int getConversationCount() {
		SQLiteDatabase db = this.getReadableDatabase();
		Cursor cursor = db.rawQuery(
				"select count(uuid) as count from conversations", null);
		cursor.moveToFirst();
		return cursor.getInt(0);
	}

	public List<Conversation> getConversations(int status) {
		List<Conversation> list = new ArrayList<Conversation>();
		SQLiteDatabase db = this.getReadableDatabase();
		String[] selectionArgs = { "" + status };
		Cursor cursor = db
				.rawQuery(
						"select * from conversations where status = ? order by created desc",
						selectionArgs);
		while (cursor.moveToNext()) {
			list.add(Conversation.fromCursor(cursor));
		}
		return list;
	}

}